curl --request POST \
  --url https://services.leadconnectorhq.com/calendars/groups/validate-slug \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'Version: <version>' \
  --data '
{
  "locationId": "ve9EPM428h8vShlRW1KT",
  "slug": "calendar-1"
}
'

{
  "available": true
}